The present disclosure relates to a display panel with a touch detection function which detects a touch event by an external proximity object, a drive circuit thereof, and an electronic unit having such a display panel with a touch detection function.
In recent years, attention has been given to a display panel configured by mounting a contact sensing device, a so-called touch panel, on a display such as a liquid crystal display or the like, or integrating the touch panel and the display, thereby causing the display to display various button images and the like to enable information input, in place of ordinary mechanical buttons. The display panel having such a touch panel is allowed not to have an input device such as a keyboard, a mouse, or a keypad and therefore, there is a growing trend to use the display panel in a portable information terminal such as a portable telephone, in addition to a computer.
There are some types of the touch panel, including an optical type, a resistive type, and a capacitance type. For example, Japanese Unexamined Patent Application Publication No. 2009-258182 has proposed a so-called in-cell type display panel with a touch detection function. According to this document, in a capacitance-type touch panel, a common electrode for display originally provided in a display is used as one of a pair of touch sensor electrodes, and the other (a touch detection electrode) is disposed to intersect this common electrode. In this display panel with a touch detection function, an AC signal applied to this common electrode is transmitted to the touch detection electrode via a capacitance between the common electrode and the touch detection electrode. Then, a touch event is detected based on a detection signal outputted from the touch detection electrode. A drive circuit that performs driving by applying this AC signal to the common electrode is formed on a TFT board made of glass or the like.